Device for testing distance between blowback nozzles of filter bag dust collector

Abstract

The utility model discloses a filter bag dust collector blowback nozzle distance test device comprising a pedestal, the pedestal is provided with a straight slide bar vertically extending up and down, the straight slide bar is slidably connected with an upper slide sleeve and a lower slide sleeve, the upper slide sleeve is in threaded connection with an upper locking nut, the end portion of the upper locking nut abuts against the straight slide bar, and the lower slide sleeve is in threaded connection with a lower locking nut. The lower sliding sleeve is in threaded connection with a lower locking nut with the end abutting against the straight sliding rod, the upper sliding sleeve is provided with an upper adjusting arm horizontally extending left and right, the upper adjusting arm is provided with a nozzle with a downward nozzle opening, the upper end of the nozzle is connected with a test gas source, and the lower sliding sleeve is provided with a lower adjusting arm horizontally extending left and right. The lower adjusting arm is provided with a replaceable cable hanging ring arranged under the nozzle. According to the test device, initial parameters are designed, nozzle parameters are verified, the optimal distance of the nozzle is verified or adjusted in an observable manner in the back flushing test, and the initial parameters are corrected, so that the optimal technical design parameters are achieved, the overall function is complete, and the practicability is high.

Description

Technical Field

[0001] The utility model relates to the technical field of test equipment, and more specifically, to a back-blowing nozzle distance test device for a filter bag dust collector. Background Art

[0002] With the improvement of national environmental protection requirements, all production processes and production points where dust is generated are required to have dust removal devices, and the most widely used dust removal equipment is the bag filter dust collector. Moreover, the volume of large bag filter dust collectors has reached several thousand m 3 Thousands of filter bags are used. Besides the quality of the filter bags themselves, another key aspect of bag-type dust collector manufacturing is the optimal distance between the nozzle of the air source for reverse-jet dust removal and the bag opening. This distance is crucial to the equipment's service life and manufacturing cost. With the widespread use and increasing scale of bag-type dust collectors, optimizing nozzle distance has become of great technical and economic significance.

[0003] The working principle of bag filter dust collector is as follows Figure 2 As shown. The dust filter bag has an elastic clamp (8) covered by the filter bag fabric and clamped on a porous partition called a flower plate. The air flow containing dust is filtered through the filter bag outside the filter bag (9) (the air pressure is higher than the inside), and the filtered clean gas is collected and discharged through the space on the isolation flower plate inside the filter bag (the air pressure is lower than the outside) (4). There is a nozzle (3) of compressed air with a higher pressure above the filter bag opening. The compressed air from the nozzle is sprayed into the filter bag opening at a certain time interval. Because the direction of the spraying air is opposite to the normal dust removal airflow, it is also called reverse spray dust removal, abbreviated as backblowing or spraying. When backblowing, the air pressure of the filter bag is high inside and low outside in the short term. The effect of backblowing allows the dust adsorbed on the outside of the filter bag to fall off, thereby maintaining the long-term filtering and ventilation capacity of the filter bag.

[0004] Backflush nozzle (3): The distance between the backflush nozzle and the filter bag opening must be scientifically determined. According to the laws of fluid mechanics, when compressed air is ejected from the nozzle, its airflow trajectory is like the flame of an inverted oil lamp (the flame of a lamp itself is also subject to the laws of fluid mechanics). The flame-shaped airflow trajectory shrinks left and right, then converges to a focal point (B), and the airflow trajectory at the focal point switches positions left and right. Above the focal point, due to the high airflow velocity and low central pressure, the surrounding air is strongly drawn toward the center under negative pressure (5). Below the focal point, the compressed air flows outward (C), forming a back pressure on the inner wall of the filter bag, achieving the purpose of reverse blowing and cleaning. The distance between the nozzle and the filter bag opening must be scientifically determined during design and installation (N). The distance is too small. The section of the filter bag near the filter bag opening is always in a negative pressure state. The section of the filter bag in a negative pressure state is sealed by dust due to the continuous adsorption of dust, and loses its dust filtration effect. This results in a loss of effective dust removal and filtration area. At the same time, the long-term high-speed contraction vortex (A) causes the fabric at the filter bag opening to be eroded by the high-speed vortex airflow, causing it to become loose and worn. Alternatively, if the filter bag opening is too far from the nozzle (high), the discharge chamber volume becomes excessive, increasing the dead space within the dust collector and ultimately leading to excessively high dust collector costs. Furthermore, if the distance is too high, the backwash airflow entering the filter bag opening is already in a highly diffused state (C), and the ejected airflow directly hits the edge of the filter bag opening, causing it to rot. This increases backwash air consumption, prematurely damages the filter bag opening, and shortens the filter bag's service life. This also causes leakage of the collected airflow, increasing dust emissions and lowering environmental emission standards.

[0005] Reasonable design and installation: The nozzle and the filter bag opening should be positioned a certain distance below the focal point of the jet. The airflow should enter the filter bag tangentially along the outer envelope of the jet. This allows the entire backflush airflow to be used for backflush, maximizing the space between the filter bag and the dust collector and maximizing the service life of the dust collector filter bag. An even greater benefit is that when the backflush airflow enters the filter bag tangentially, it creates a strong standing wave vibration on the inner wall of the filter bag. This vibration strongly shakes off dust adsorbed on the outer surface of the filter bag, achieving a dust removal effect that even exceeds the original purpose of backflush.

[0006] In summary, the design of the distance between the nozzle and the filter bag opening has become of great technical and economic significance. This patented testing and testing device provides an intuitive and scientific means of determining the optimal distance between the nozzle and the filter bag opening. It will have extremely effective engineering applications in two key areas. Accordingly, this utility model proposes a device for testing the distance between the backflush nozzle and the filter bag opening of a filter bag dust collector. Utility Model Content

[0007] The purpose of the utility model is to overcome the above-mentioned deficiencies in the prior art and to provide a device for testing the back-blowing nozzle distance of a bag filter dust collector.

[0008] In order to solve the above technical problems, the purpose of the present invention is achieved as follows: the utility model involves a filter bag dust collector backblowing nozzle distance test device, including a base, the base is provided with a straight sliding rod extending vertically up and down, the straight sliding rod is slidably connected to an upper sliding sleeve and a lower sliding sleeve, the upper sliding sleeve is threadedly connected to an upper locking nut that rests on the straight sliding rod at its end, the lower sleeve is threadedly connected to a lower locking nut that rests on the straight sliding rod at its end. The upper sliding sleeve is provided with an upper adjusting arm extending horizontally left and right, the upper adjusting arm is provided with a nozzle with a nozzle facing downward, the upper end of the nozzle is connected to a test air source, the lower sleeve is provided with a lower adjusting arm extending horizontally left and right, the lower adjusting arm is provided with a replaceable wire hanging ring directly below the nozzle, and the replaceable wire hanging ring is coaxially arranged with the nozzle.

[0009] The utility model is further configured as follows: a pulse electromagnetic valve is serially arranged on the test gas source.

[0010] The utility model is further configured as follows: the straight sliding rod is provided with a scale arranged up and down.

[0011] The utility model is further configured as follows: a holding magnet is provided on the base.

[0012] The utility model is further configured as follows: the upper locking nut and the lower locking nut are both hand-tightening locking screws.

[0013] To sum up, the utility model has the following beneficial effects: the filter bag dust collector backblowing nozzle distance test device involved in the utility model verifies the nozzle parameters according to the initial design parameters, verifies or adjusts the optimal nozzle distance by observable means during the backblowing test, and corrects the initial parameters to achieve the best technical design parameters. The overall function is complete and the practicality is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0015] Figure 2 It is a schematic diagram of pulse injection of bag filter dust collector. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the preferred embodiments of the present invention are described below in conjunction with specific examples. However, it should be understood that these descriptions are only for the purpose of further illustrating the features and advantages of the present invention, and are not intended to limit the patent claims of the present invention. Based on the examples in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0017] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0018] Example 1

[0019] See also Figure 1 As shown, a filter bag dust collector backblowing nozzle distance test device involved in this embodiment includes a base 100, which is provided with a straight sliding rod 101 extending vertically up and down, and an upper sliding sleeve 102 and a lower sliding sleeve 103 are slidably connected to the straight sliding rod 101, and the upper sliding sleeve 102 is threadedly connected to an upper locking nut 104 whose end rests against the straight sliding rod, and the lower sliding sleeve 103 is threadedly connected to a lower locking nut 105 whose end rests against the straight sliding rod. The upper sliding sleeve 102 is provided with an upper adjusting arm 106 extending horizontally left and right, and the upper adjusting arm 106 is provided with a nozzle 107 with a nozzle facing downward, and the upper end of the nozzle 107 is connected to a test air source, and the lower sliding sleeve 103 is provided with a lower adjusting arm 108 extending horizontally left and right, and the lower adjusting arm 108 is provided with a replaceable wire hanging ring 109 located directly below the nozzle, and the replaceable wire hanging ring 109 is coaxially arranged with the nozzle 107.

[0020] Furthermore, a pulse electromagnetic valve 110 is connected in series to the test gas source.

[0021] Furthermore, the straight sliding rod 101 is provided with scales arranged up and down.

[0022] Furthermore, a holding magnet 111 is provided on the base 100 .

[0023] Furthermore, the upper locking nut 104 and the lower locking nut 105 are both hand-tightened locking screws.

[0024] In this implementation plan, the functions of each functional component are described as follows:

[0025] a. Upper Adjustment Arm 106: The distance from the thread loop can be adjusted up and down using a handwheel on the center slide. The top of the upper adjustment arm's crossbar allows the nozzle to be inserted into a replaceable horizontal retaining ring. In actual use, the nozzle should be flush with the lower edge of the retaining ring to ensure uniform parameter dimensional measurement. A nozzle with the desired spraying parameters is fixed within the ring, and a solenoid valve simulates the nozzle's pulsed jet. When adjusting and testing an installed bag filter on-site, the nozzle should be aligned with the center of the nozzle retaining ring. If a nozzle stub is not present, the upper surface of the retaining ring should be flush with the nozzle. However, the distance should be calculated from the upper surface of the retaining ring.

[0026] b. Sliding rod 101 with scale: It is a cylindrical cross section with a guide groove. The upper and lower working hand wheels are guided by the guide groove to slide up and down. The nozzle distance can be read according to the scale on the rod at the positioning point.

[0027] c. Lower adjustment arm 108: The lower sliding adjustment arm can be slid up and down on the slide rod, and the head of the sliding adjustment arm can be screwed to hang the wire hanging ring of each inner diameter matching the center size (this inner diameter is the same as the inner diameter of the filter bag).

[0028] d. Base 100: The base secures the straight slide rod, maintaining perpendicularity between the rod and the base. Four magnets are mounted on the bottom of the base. During use, the magnets attract the test device to the flat iron plate, securing it concentrically with the center of the filter bag being tested and the nozzle, preventing vibration and displacement caused by the nozzle's spraying action.

[0029] The experimental device's operating mechanism is as follows: When the string loop is in the contraction zone, the hanging line contracts and drifts inward (negative pressure). The contraction gradually weakens as it approaches the focal point, and the vertical line remains stationary at the focal point (zero pressure). After passing the focal point, the string loop moves downward, and the vertical line begins to drift outward (positive pressure), with the outward drift becoming more intense as it moves downward from the focal point.

[0030] The optimal distance between the bag opening and the nozzle is determined as follows: after the thread passes the focal point and moves downward, the optimal spray spacing is reached when the thread slightly floats outward. Above the zero-pressure point, the spray spacing is too small, and the section near the bag opening is under negative pressure. This means that dust is adsorbed in this section of the bag opening, but it cannot be removed by back-spray, wasting bag resources. Furthermore, due to the strong negative pressure vortex in the section above the focal point, the fibers on the inner surface of the bag opening become loose and damaged. In this state, to ensure that the effective bag area is fully utilized for filtering, the bag length must be increased, which in turn increases the metal and bag manufacturing costs of the dust collector. If the distance between the nozzle and the bag opening is too large, allowing the back-blowing airflow to diffuse outside the bag opening, the bag opening will be damaged, significantly reducing the bag's service life. Furthermore, due to the excessive nozzle distance, the exhaust chamber is designed to be too high, increasing the metal production costs of the dust collector.

[0031] Among them, the test application before commissioning and during the production process: before the project is installed and put into operation and during the production process, there are some factors that may affect the nozzle spacing due to manufacturing and installation. In addition, due to vibration during the production process, thermal expansion and contraction, and loosening of fixings, as well as changes in air source pressure and pulse injection parameters, the nozzle spacing may deviate from the optimal injection distance. In this case, it is necessary to re-verify the nozzle spacing. If necessary, the concentricity of the nozzle of the injection main pipe and the center of the filter bag opening, as well as the height of the injection main pipe and the filter bag opening (which determines the distance between the nozzle and the filter bag opening) should be adjusted.

[0032] In addition, the pulse electromagnetic valve 110 is provided to provide a pulse gas source.

[0033] In addition, the scale can be set to intuitively display the adjusted height.

[0034] In addition, the holding magnet 111 is provided for positioning.

[0035] In addition, by setting the upper locking nut 104 and the lower locking nut 105 as hand-tightening locking screws, rotation adjustment is convenient.

[0036] The filter bag dust collector backflush nozzle distance test device involved in the utility model verifies the nozzle parameters according to the initial design parameters, verifies or adjusts the optimal nozzle distance by observable means during the backflush test, and corrects the initial design parameters to achieve the best technical design parameters. The overall function is complete and the practicability is strong.

[0037] Unless otherwise specified, in the present invention, if there are terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicating orientation or positional relationship, they are based on the orientation or positional relationship actually shown and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing orientation or positional relationship in the present invention are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, they can combine the embodiments and understand the specific meanings of the above terms according to specific circumstances.

[0038] Unless otherwise specified or limited, the terms "disposed," "connected," and "connected" in this utility model should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0039] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art based on the concepts of the present invention through logical analysis, reasoning, or limited experimentation based on the existing technology should be within the scope of protection defined by the claims.

Claims

1. A filter bag dust collector back-blowing nozzle distance test device, including a base, is characterized by: The base is provided with a straight sliding rod extending vertically up and down, and the straight sliding rod is slidably connected to an upper sliding sleeve and a lower sliding sleeve, the upper sliding sleeve is threadedly connected to an upper locking nut whose end rests against the straight sliding rod, and the lower sliding sleeve is threadedly connected to a lower locking nut whose end rests against the straight sliding rod. The upper sliding sleeve is provided with an upper adjusting arm extending horizontally left and right, the upper adjusting arm is provided with a nozzle with a nozzle facing downward, the upper end of the nozzle is connected to a test air source, the lower sliding sleeve is provided with a lower adjusting arm extending horizontally left and right, and the lower adjusting arm is provided with a replaceable wire hanging ring directly below the nozzle, and the replaceable wire hanging ring is coaxial with the nozzle.

2. The back-blowing nozzle distance test device for a bag filter dust collector according to claim 1, characterized in that: A pulse electromagnetic valve is serially arranged on the test gas source.

3. The back-blowing nozzle distance test device for a bag filter dust collector according to claim 1 or 2, characterized in that: The straight sliding rod is provided with a scale arranged up and down.

4. The back-blowing nozzle distance test device for a bag filter dust collector according to claim 3, characterized in that: A holding magnet is provided on the base.

5. The back-blowing nozzle distance test device for a bag filter dust collector according to claim 1, characterized in that: The upper locking nut and the lower locking nut are both hand-tightening locking screws.

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